3. Brightness: The high-sensitivity photosensitive sensor can automatically adjust the display brightness according to the brightness of the use environment, or manually set the high, medium and low three-level brightness.

4. Memory function: Built-in a CR2016 button battery, when the external power supply is powered off, the time and various settings are unchanged, and the time after the external power supply is cut off is not displayed, so as to avoid repeating the settings after the next use.